eMarketer estimates nearly 116 million Americans will use a smartphone at least monthly by the end of this year, up from 93.1 million in 2011. By 2013, they will represent over half of all mobile phone users, and by 2016, nearly three in five consumers will have a smartphone.

Turns out, eMarketer underestimated how quickly they’d be the majority:

50.4% of U.S. mobile subscribers owned smartphones in March 2012, up from 47.8% in December 2011, according to Q1 2012 data from Nielsen Mobile Insights. Broken down by operating system: Android was first with a 48.5% share, followed by Apple’s iOS (32%), RIM‘s BlackBerry (11.6%), Windows Mobile (4.1%), Windows Phone (1.7%), and other (2.1%).

What’s interesting is how this has changed user behavior. People with these devices are “always on.” They are constantly consuming content, generally in small increments. A few minutes of news, a funny video, 10 minutes of a game while commuting. The issue becomes how are the old guard of content producers adapting? It’s great that TV shows are available across platforms, but the study tells us that a 20 minute TV episode is unlikely to hit the sweet spot of consumption. Could it be that the nature of TV itself changes? What made the 30 or 60 minute episode king other than an ability to tell people when to tune in?

So while “consuming content in frequent, small portions means more touch points for marketers,” it seems to me that users want to be touched differently from how they’ve been in the past. If we’re producing content, we need to keep that in mind. And I’ll just leave it there before we head into weirdness.